Protein engineering of fucosyltransferases

Protein engineering of fucosyltransferases for the production of human milk oligosaccharides

Human milk oligosaccharides (HMO) are found in large quantities in breast milk. The trisaccharide 2′-fucosyl-lactose (2′-FL) is one of the most abundant oligosaccharides and is approved for use in infant formula. Since chemical production is inefficient, biosynthetic routes are favored – in particular whole-cell syntheses with recombinant Escherichia coli. One hypothesis based on the findings to date is that low fucosyltransferase activity is one of the limiting factors in 2′-FL synthesis. This is due to two properties of the enzymes known to date: low soluble expression in E. coli and low turnover numbers with the substrate lactose. Improved fucosyltransferase variants are therefore to be made available as part of the project. Improved enzymes will be introduced at the genetic level into currently available production strains. In collaboration with the Institute of Bioprocess Engineering at the Technical University of Munich, where further limiting steps in microbial metabolism are being identified, targeted genetic modifications are being made to further increase the performance of the production strains.

This project is funded by the German Research Foundation (DFG).